1. Field of the Invention
The present invention relates to semiconductor wafer processing systems, and more specifically, to heating fluids in a proximity head.
2. Description of the Related Art
Semiconductor wafer fabrication typically involves multiple repeated fabrication steps, such as implantation, material deposition, planarization, and etching. After each fabrication step, residue can remain on a surface of a semiconductor wafer. Thus, between the fabrication steps, a cleaning step is typically used to remove particulates and other undesirable material that remain on the surface of the semiconductor wafer. Exemplary particulates can include silicon dust, silica, slurry residue, metal flakes, and silicate particles.
The cleaning step can include a rinse step, a spin step, and a dry step. During the rinse step, a fluid delivery device, such as a spray device or an immersion device, can apply a cleaning fluid to wet the surface of the semiconductor wafer. For example, the cleaning fluid can be sprayed onto the surface of the semiconductor wafer with the spray device. Alternatively, the semiconductor wafer can be immersed in the cleaning fluid within the immersion device. After the rinse step, the semiconductor wafer can be rotated to spin off the particulates along with the cleaning fluid. Subsequently, a drying step can dry remaining droplets on the surface of the semiconductor wafer. During the cleaning step or other semiconductor wafer fabrication steps, it may be desirable to heat the fluid applied to the surface of the semiconductor wafer.
Typical heating mechanisms for semiconductor wafer processing systems have included a heater connected to a fluid source. The fluid source delivers fluid, such as the cleaning fluid, to the heater, which heats the cleaning fluid to some desired temperature. Subsequently, the heated cleaning fluid propagates to the spray device or the immersion device.
However, using the steps previously described in current semiconductor wafer processing systems may be inefficient. For example, the heated cleaning fluid may experience heat loss while traveling from the heater to the fluid delivery device. Thus, when the heated cleaning fluid touches the surface of the semiconductor wafer, the temperature of the heated cleaning fluid may be lower than the desired temperature.
In view of the foregoing, what is needed is an apparatus and a method for heating fluid in a semiconductor wafer processing system that enables heated fluid to be delivered to a semiconductor wafer at a desired temperature.